908 0r 902?

[RonSSS]

From your date codes--if those frams are the originals for your drivers it may confirm what I've heard--that the light diaphragms were discontinued in the late 70's. Your 806's from 1979 have the light diaphragms, and your 902's from 1980 do not just as my 902's from 1981 do not. I wouldn't be surprised if 1979 was the last batch of light diaphragms partially based on these date codes. I guess you sometimes have to fill in the blanks with observations like these as much of this stuff was not documented by Altec at the time (or if it was, the documentation is hard to find/hasn't survived the years)....

I'll yard the 19's apart his weekend and see what they are. I may be a total liar, I'm not sure now.

Ok, I'm a liar.

Ron